Erwin hoefa and hans heyna



Patented June 10, 1930 UNITED STATES PATENT OFFICE ERWIN HOFFJA AND HANS HEYNA, OF HOCH ST-ON-MAIN, GERMANY, ASSTGNORS '10 GENERAL ANILINE WORKS, INC., OF NEW YORK,

WARE

N. Y., A CORPORATION OF DELA- NEW VAT DYESTUFFS AND A IEIROGESS OF PREPARING THEM No Drawing. Application filed October 13, 1927, Serial No. 228,039, and in Germany October 23, 1926.

The present invention relates to new vatdyestuffs and a process of'pr'eparing them.

Our invention is based on the discovery that such dyestuifs as contain the group:

cm H A 3 4 somooon wherein m stands for CN, CONT-I or COOH with an agent capable of closing the ring. The hydroxythionaphthene is transformed into the corresponding thioindigo dyestufi by oxidizing it according to the usual methods. The following examples serve to illustrate our invention, but they are not intended to limit it thereto; the parts being parts by weightz- 1. 21 parts of 3-methylbenzene-l-thioglycol-2-carboxylic acid nitrile are dissolved in 600 parts of Water and 10 parts of caustic soda solution of 40 B. When dissolution 40 is complete, there are added 90 parts of caustic soda solution of 40 B and the Whole is stirred for 2 hours at 80 to 85 C. The separation of the sodium salt of t-methyl-3-amino- 1-thionaphthene-2-carboxylic acid begins already when the solution is heated, and after addition of parts of sodium chloride it is nearly complete when the solution has cooled. The sodium salt is filtered and washed with a solution of sodium chloride; the moist paste 50 is dissolved in 20 time's-its weight of water solution and sodium bisulfite.

while adding small quantities of caustic soda The product is filtered, the filtrate is acidified with dilute sulfuric acid and then heated on the water bath until the formation of hydroxythionaphthene is complete. After cooling, the hydroxythionaphthene is filtered by suction, Washed and transformed into the HF-dimethylbisthionaphthene-indigoaccording to known methods.

The said dyestulf gives a golden-yellow vat which dyes cotton very clear red tints of extraordinary good fastness to light.

The parent body can be made bysubstituti ing cyanogen in the '1-methyl-2-amino-3-nitrobenzene for the amino-group, reducing the nitro-group to the amino-group and introducing the thioglycollic acid residueby way of the diazo-compound.

f 2. 15 parts of 3-methylbenzene-1-thiogly- 'col-2-carboxylic acid are melted with 150 parts of caustic soda and 20 parts of water for 1 hour at 180 to 200 C. After cooling, the mass is dissolved in 500 parts of water, filtered and the filtrate is oxidized to the dyestufli' in the usual manner. The dyestuff is identical with that obtainable according to Example 1.

The parent material can be made by transforming l-methyl-2-amino-3-chlorobenzene by way of the-diazo-compound into the cyanogen compound, saponifying the cyanogen group to the carboxyl group and substituting for the chlorine the residue SCH COOH, for instance by the process described in German Patent No. 189,200. 7

'3. 32 parts of l-methyl-6-chlor-2.3-dihy dro-3-ketothionaphthene-2- (4J-dimethylamino) -anile of the formula:

co i

OH: O a S r are heated to boiling with 16 parts of -met yl-3-hydroxy-thionaphthene in 600 parts of glacial acetic acid until the formation of the dyestuif is complete. After cooling, the

dyestufl' is filtered by suction and washed until neutral. It dyes cotton red tints of goods,

fastness to boiling and to light. When dissolved in sulfuric acid, it gives a bluish-green solution.

4. 21 parts of 5.7 -dichlorisatine are heated in 200 parts of benzene with 21 parts of phosphorus pentachloride until the whole is dissolved and to the mass is then added a suspension of 16. parts of 4-methyl-3-hydroxy thionaphthene in 100 parts of benzene, while well stirring. The separation of the dyestuff begins very soon. When it is complete, the dyestufi' is isolated from the benzene. It dyes cotton a violet shade of excellent fastness to boiling and light. Its solution in sulfuric acid is of a green color."

-We claim: v

1. As new products, indigoid vat-dyestuffs containing the following atomic group:

t CH; O

t H \C= H S'/ n which dyestufl's possess excellent properties regarding fastness.

2. As new products, the vat-dyestuifs of the following formula: 7

wherein m stands for hydrogen or a halogen I atom which vat-dyestuffs possess excellent properties regarding fastness.

3. As a new product, the vat-dyestufi' of,

the following formula which dyestufi dissolves into a vat with a golden-yellow color and gives on cotton very clear red shades remarkable for their extraordinary goods fastness to light.

In testimony whereof, we aflix our signatures.

ERWIN HOFFA.

HANS HEYNA. 

